The goal of this application is to distinguish myself as an independent investigator in cancer prevention and control. I will accomplish this goal through excellent multidisciplinary mentorship, a targeted education plan, and the completion of an innovative research project testing the effects of a group psychological intervention on immune function and psychological function among women at elevated risk for breast cancer. Chronic stress can impair immune function, including immune response to vaccines. This has important implications for cancer control and prevention because tumor vaccines are emerging as tools for cancer treatment and prevention, and the cohort that would benefit from the vaccines is likely to be stressed. Women at elevated risk for breast cancer experience significant levels of distress that have been associated with immune function decrements. Interventions to treat distress-related immune decrements among these women are needed because these women will be among the first candidates for breast cancer vaccines. In theory, stress-management interventions should improve immune function and response to vaccines, but the findings to date are mixed, in part because most intervention studies have been done with medical patients who by nature have immune confounds. Thus, it is unknown how stress management interventions effect immune function in stressed but otherwise healthy people, such as women at elevated risk for breast cancer. To address this gap, the proposed investigation will conduct a randomized, clinical trial to test the efficacy of a cognitive behavioral stress management (CBSM) group intervention on immune response to vaccine and distress among women at elevated risk for breast cancer.